Lift-up sink overflow

We seems to be suffering from an excess of water on the floor of the shower compartment. I've narrowed it down to water escaping under the lift-up sink when we empty it. The water then dribbles down around the loo seat . It seems to happen whether we lift with gusto or tip it gently when it's not looking. Are we suffering alone? Is there an obvious reason why I have to go to bed with wet feet? Before anyone suggests this as a solution, I have checked the drain from the channel behind the sink and it's clear. It seems to happen whether the waste tank is full or empty and at any state of the tide.
Anyone else got the same problem?
Cheers
John

No, not had any water overflow from sink yet, I tip it slowly and don`t put a lot of water in the basin, hope I am not tempting providence here.

Just like Daisy Mae, we tip ours very slowly and have not had a problem. Was the van level?

Yes. The van's always level, or nearly so. The sink spills happen whether we tip slowly or not. I'm thinking that I might have to put a bead of silicon across the back of the sink to create a better lip and so allow the tipped water to break away better.

There is an existing thread about this.
Pull the sink up and out of its slots and see if the plughole is blocked.
PeteJ

Thanks Pete but as I said, the plug is as clean as a whistle.
I looked for any earlier threads but couldn't find anything. Could you please put up a link?
John

How about taking the tip up sink out and pour water down into the trough to see how well it goes down the plug hole.

PB

Thanks PB. Yes, I tried that. I sent a bucket full down in a bit of a rush and it all drained away well. The underflow (in that it is escaping under the tipped up sink) is happening when only small amounts of water are being tipped away. The sink isn't distorted at all so there's no obvious reason why the water doesn't simply tip out and drain away.
Pjkxpjkx tells me (above) that there is a thread on this already so I'm hopeful that he'll point me in the right direction since I can't find it. Strange that no-one else has this problem.
John

I understand what you're getting at, the sink in our Exec does this too.

I'm not too certain what method works best to prevent it and I'm concerned that it might not be a good thing if water escapes down the back of the shower wall as well as into the shower tray.

Certain recent events have made me far more interested in water on the floor than I used to to be. 

WJ, I can't find a post on the same problem as yours either.

There wouldn't be a crack in the sink that is allowing water into the void between the two skins?
When you tip it up, it could be coming out from inbetween.

PB

This thread is useless without pictures or a video in this case, I might make one.

There's definitely no crack in our tip up sink PB, it's similar to the times when the milk flow sticks to the side of the bottle rather than a stream that separates from the lip and into the cup, sometimes it does this, sometimes not (if I interpret WJ's OP correctly).

Meanchris. You're about right. There's no crack in our sink and you have interpreted my OP correctly (good milk bottle analogy!).
Yes, a picture won't show much unless I use coloured water but a video might show that even tipping the sink up slowly with not much water in still results in overflow (underflow)
John

Sounds to me that your idea of a bead of silicon sealant along the back of the sink will solve your problem,  could you polish it to remove water surface tension? This probably sounds daft but we always leave the 2 plugs in the shower tray so that nothing comes back out and wetting our feet.

Yes Paul, the plugs are in and the water's definitely coming from the sink tip-up. I'll try a polish though. Good idea.
Pip Pip
John

Perhaps this is the aforementioned thread:

[You must be registered and logged in to see this link.]

G

If t is, then you are quite right.
But is there a solution?
John

Hi John
I had a similar problem last year with the occasional  wet shower tray, mine  was caused by a very small leak from the shower tap, only really evident when I took the tap apart, fairly unlikely for you to have the same problem -------- but you never know.
Batch     
( Also from Weymouth )

Thanks Batch but it's definitely coming under the sink as we tip it. I'm about to try Paul's suggestion (above) and give the back (hidden) part of the sink a good waxing to try and reduce surface tension.
I'll look out for you around town!
John

These sinks usually pivot on two "pins" which fit into slots on either side of the frame. Is there anything preventing the two pins from reaching the bottom of the slots ? If this were the case, the lower edge of the sink would not be far enough into the opening to drain correctly.
Keith

I refilled my MH today, after tipping out the water  from  the tip up basin I didn`t have any water any where it shouldn`t be, had a good look at the sink, as KMRTOPAZ said there are two plastic pins either side of the basin, I tested by putting slight pressure on the sink and it would go in further towards the back, not much but there was still some play there, so I could see that if there was a lot of water it could hit the back of the draining channel and come out over the toilet, so when I rinsed the tank out and drained through the taps I held the tip up basin more towards me rather than pushing it backwards and emptied the basin. I didn`t realise before that there was that much play.
I know it isn`t the answer to the OP question, just trying to see what it couldn`t be then perhaps some one will come with what it is.  Good luck.
Margaret

Thanks PJKXPJKX I had seen that thread but it doesn't really cover the problem that we face although Gram (in that thread) seems to be suffering too. Certainly the trough behind the sink has more capacity than the sink and so regardless of whether the sink is blocked (ours isn't) there should be no dribbles.
I'm beginning to think that, along with the Turin Shroud, this will have to be ticked off as one of life's mysteries.
Thanks to everyone who has come up with suggestions
John

To put this thread to bed .....


Paul 300358 had the idea of polishing the rear of the sink and this has certainly helped as long as the tipping is fairly slow. It's not perfect but a good idea and certainly much better than it was.

We did learn the hard way!! LIFT slowly and pour , no more spillage.